1. Field of the Invention
This invention relates to broadcast information systems and, more particularly, to broadcast interactive multimedia systems which access hyperlinked multimedia databases.
2. Description of the Background Art
It is widely recognized that there is value in systems which allow each individual user to interactively navigate hyperlinked multimedia (hypermedia) databases. For example, one type of system includes the commercially popular multimedia CD-ROM based encyclopedias such as Microsoft's Encarta and Compton's Interactive Encyclopedia. Another example of an interactive hypermedia database that is growing in popularity is the World Wide Web (WWW). WWW is an Internet-based distributed hypermedia database which is primarily accessed using the Mosaic client interface software.
These two examples of hypermedia represent two broad classes of hypermedia which presently exist. The first class is characterized by systems wherein the database is stored locally, usually either on a fixed disk or a CD-ROM. Systems of this class exhibit relatively rapid access times but they are not easily updated with new information and are limited in size by storage costs.
The second class is comprised of systems wherein the database is remote and shared by many users. In this case, the database may be much larger than the local-type databases since the storage costs can be shared over a large number of users. Data elements are sent via a bi-directional transmission medium in response to user-generated requests. Systems of this class may exhibit relatively poor access times due to bottlenecks in the transmission medium and high demand load on the shared storage media. The cost for use of the transmission media, that is, connect time, may represent a significant fraction of the total cost of retrieval of the information.
With the foregoing context-setting discussion in mind, besides the classes of hypermedia systems considered above, other examples of systems which access or deliver text, data, and/or video in an interactive manner have been presented and discussed in the literature.
Representative of the type of system broadly referred to as a "teletext" system or "videotext" system is U.S. Pat. No. 4,614,972, entitled "Teletext Receiver", issued to Motsch et al (hereinafter Motsch). In order to clearly distinguish the system of this reference from the present invention, as well as providing a point of departure for other types of systems discussed shortly in other references, Motsch is now considered is some detail.
The term teletext is used for an information transmission system wherein, besides a conventional television image, additional information can be transmitted in unused lines of the television image. The television receiver, when suitably equipped with a decoder for this additional information, can display this ancillary information. The teletext information originates from a database in which up to several hundred pieces of information are stored.
In a conventional teletext system, the additional information is coded in a digital format and is organized according to a standard particular to a country or regional areas in the world. Illustratively, when using a standard, data is partitioned into bytes which are then sequentially grouped into a block; a header is then added to the block to form a packet, which is the largest piece of information sent during any one interval. To re-generate the additional information at the receiver, several packets are de-multiplexed and sorted to restore the time orientation.
In the system considered by Motsch, separate pieces of information can be multiplexed within the same digital channel by means of imposing an overlay structure to form "articles". In addition, a number of articles may be grouped together to define a "magazine". Such a structure fosters a communication arrangement wherein both information to be displayed directly on the receiver and information which aids in the direct display of such information are multiplexed. Each article is typically composed of four consecutive fields: an article start; an article heading; data; and an article end. Of particular relevance is the article heading, which consists of, in part, a classification sequence chosen by a "classifier entity", such as a knowledgeable individual. The sequence allows a user located at a receiver to select an article, for instance, by its number; this number could be learned from an index which is transmitted as the initial piece of information sent to the user.
In line with the standard considered by Motsch, the classification sequence was made up of three consecutive bytes (C1, C2, C3), each of which had 16 possible values (0-9, A-F). In the standard, only three classes are defined, namely: (1) a class wherein C1C2C3 ranged between 001 and 999; (2) a class wherein C1=C2=C3=0; and (3) a class wherein at least one of C1, C2, C3 equals A, with the others being between 0 and 9. The user selects an article by typing on a keyboard a number having three digits (called A1, A2, A3) between 001 and 999; it is clear that this selection results in user access to only those articles in the first class.
In the first teletext systems, the information for a single display on the receiver (a "page") was contained entirely within an article. The choice of a page from among the cyclically transmitted articles was effected by comparison of the A1A2A3 sequence to the C1C2C3 sequence in an incoming article. However, over time, articles became much more complex and the information corresponding to a desired page to be displayed could no longer be included within a single article. As an example, a so-called "teleloading" article may be required to help display several pages; teleloading information includes, for instance, page bottom information or range of color for the display of the pages. Each of these supplementary articles relating to inter-dependent pages is given a separate article number. Thus, a teletext receiver must take into account several articles for a single set of A1, A2, A3 digits.
The contribution of Motsch is that of defining a fourth class of articles so that at least one of the bytes C1, C2, C3 has a value between B and F. Certain subclasses are defined within this fourth class so that the following methodology may be carried out: bytes C1, C2, C3 are compared to A1, A2, A3 as well as a set of threshold bytes (B1, B2, B3), and from the results of the comparison, the acquisition and storage of incoming articles is decided. Examples of subclasses include: if Cl=F, then the article must be acquired and stored; if C1.noteq.B or F, then, after the obligatory articles are stored, articles with the highest value (EFF) down to the lowest (E00) must be acquired and stored, if there is sufficient storage capacity. After each cycle, the state of the storage device is examined, and the threshold values (B1, B2, B3) are adjusted accordingly to store more or less articles, as the case may be.
By way of distinguishing this reference, it is clear that there is no teaching or suggestion in Motsch of an intelligence-gathering process embedded in the receiver which monitors selection patterns of the user, and which utilizes the results of monitoring in an adaptation or learning process to capture and then store articles that the user may have an interest in as inferred from the user's implicit pattern of selection. In addition, there is no mechanism in which the user may create an initial user profile setting forth the user's preference for articles categorized by classification, and then have the user profile dynamically modified by the learning process. Also, there is no consideration in Motsch of classifying information contained in an article into a plurality of classes based on a plurality of interests which different users of the information may express, either explicitly or implicitly by the user's selection pattern. Furthermore, once different interest categories are allowed for, it is also beneficial to identify different levels of interest for each of the categories to further aid in the information selection process; Motsch does not even suggest such a level of differentiation. Also, there is no suggestion in Motsch that the classification process utilizes parameters other than a single, fixed classification sequence; other parameters or attributes may be utilized in accordance with aspects of the present invention including, for example, the usefulness of the content of a magazine or article as a function of time. Moreover, the use of a hyperlink is not taught or suggested in Motsch, that is, a first article which shares a common interest with a second article does not explicitly contain a pointer to the second article. Finally, Motsch merely teaches a broadcast cycle in which all information is repeated on a periodic, fixed basis within the cycle; there is no suggestion that certain information may be repeated more frequently than other information, depending on the importance of the information, or the size of the information, or the utility in time of the information.
A type of improvement utilized by many videotext systems that is not covered by Motsch is important enough to mention although, while appealing at first glance, the overall improvement to the operation of videotext systems is marginal. Such an improvement is discerned from the perusal of U.S. Pat. No. 4,679,083 issued to Schmitz et al (hereinafter Schmitz). Schmitz is representative of videotext (as well as other types of data-gathering systems) which rely upon the linear nature of the cyclic transmissions to a videotext receiver. It is empirically known that if a user has an interest in a certain page, then there is a great likelihood that the pages arriving just prior to and/or just after the desired page will also be of interest to the user. Thus, certain systems are arranged to store likely relevant pages in a linear fashion, that is, one after another in time of arrival. If a user then desires access to a "nearby" page, the page is accessed directly from storage rather than awaiting the arrival of the information during the next successive cycle. Since a rather rudimentary model for user interest is applied, namely, high relevancy of juxtaposed pages, this so-called linear store and access is only marginally efficient compared to the efficiencies fostered by the present invention.
Another improvement utilized in a subset of teletext systems is presented in U.S. Pat. No. 4,388,645 issued to Cox et al (hereinafter Cox). Oftentimes, teletext communication provided from an orbiting satellite is received by a cable head-end operator and re-broadcast to a plurality of cable subscribers. Teletext information may include multiple pages of a programming guide or the like identifying the content of television programming signals being transmitted by the satellite. The cable head-end facility may then include a teletext decoder with local memory to acquire and store the pages representative of the cable guide. The cable guide may then be re-transmitted at selected times during the day to inform the cable subscribers of the programming to be expected during upcoming intervals. This arrangement is merely a variation to the teachings of Motsch in that only a certain types of inter-related articles are acquired in stored for eventual re-transmission by an intermediary.
Representative of another type of information-providing system based on user interaction is the USENET system. USENET is a distributed computerized news system commonly associated with the Internet--a network which is composed of thousands of interconnected computer systems. In effect, USENET is a system of distributed databases scattered on computer systems throughout the Internet. Many services are available on USENET, ranging from technical discussions of many aspects of computer, scientific topics such as mathematics or physics, and even to recreational topics such as sports or movies. Central to USENET is the notion of Newsgroups. A newsgroup is a grouping of articles with a related topic; for instance, some examples of newsgroups include "sci.physics" and "rec.movies" corresponding, respectively, to physics under science and movies under recreation. The Newsgroups are arranged in hierarchical order so that related topics are grouped together. Each of these Newsgroups contains a list of articles which are usually of a transient nature and generally are removed from the news server in about one week.
Connections between the computers that participate in the distributed databases comprising USENET communicate with each other and create a set of data that is fed (one-way) to other computer systems that do not participate in maintaining the distributed databases. The administrators of these other computers choose to receive the newsgroups that might be of interest to their users. These computers, in turn, may send the subset of data that they receive downstream to other computers (again, one-way). When a user calls in with a modem to read the news, the user is communicating with one of these computers which received this information through a one-way link. From this brief description, it is apparent that there is no capability in the combination of the USENET and local systems to "learn" of the topical interest of each local user and to guide each such user through the topical list available to the local user in an expedited fashion. (This is true even if all available articles are downloaded, that is, there is no filtering of articles by the administrator.) In short, there is no intelligence in the combination--the user must explicitly pick-and-choose the desired articles. In addition, the limitations presented above with respect to Motsch are also found as deficiencies in the USENET system because no attribute-type information is typically imparted along with the basic information contained in the available material.
Yet another example of an interactive system is the StarSight system made available through StarSight Telecast, Inc. The system is based around a display grid that shows 90 minutes of programming at a time accessible from a user's TV, as provided via over-the-air TV, cable, and/or satellite. The display grid is shown on a TV screen--the StarSight hardware may be incorporated into the TV receiver or stand-alone equipment. Information to populate the grid is generally supplied during the vertical blanking interval of the standard TV signal. The user can scan program information seven days into the future in 90 minute increments. Using a remote, hand-held type unit to control the demultiplexing unit, the user can highlight a show on the grid and then obtain a capsule description of the contents of the show on the screen. If the user desires to watch the program highlighted, a button on the remote unit is pushed to switch directly to the show. It is also possible to record a show in the future; a push of a button automatically sets an associated VCR via the demultiplexing unit.
The StarSight system allows the user to scroll through a list of all the programs coming up on a channel. Also, whenever a channel is changed, the user sees a display that includes the name of the show, a capsule description, the channel name, and the time remaining in the show. Moreover, it is also possible to search for current and future shows by theme according to categories, such as Movies, Sports, and Specials. In addition, categories are broken down into subcategories so that, for example, Sports may further include Football, Tennis, and Sports Talk. Finally, it is also possible to customize the channel guide in that the channels that the user rarely accesses can be removed upon the initial display; this customization is not automatic--direct user interaction with the StarSight system is required.
It is apparent from this summary of the features of the StarSight system that many of the limitations already discussed with respect to the prior systems also are present in the StarSight system. As one instance, there is no teaching or suggestion that user activity is monitored at the demultiplexing unit so as to learn about user preferences and then dynamically alter the system selection process accordingly. This follows from the fact that the amount of information to be conveyed in the StarSight system, by its very nature, is minuscule compared to the interactive databases such as found on World Wide Web and USENET. As another instance, the type of information provided by the StarSight system is fixed in time by program scheduling, so the usefulness of the information as a function of time is a virtually meaningless measure.
A final class of interactive system that is presently available is the Digital Satellite System (a trademark of Hughes Communications), which uses satellite technology to deliver television programming to a user's home. The programs are broadcast in digital form, and processed by a receiver upon detection by a small dish antenna located at the user's premises. A remote control is used in conjunction with the receiver to navigate an on-screen programming guide. The user can sort the guide so that only specific types of programs are displayed. For example, the user can select the Sports category, and only current and upcoming sports are displayed. There is a menu function that allows each user to customize the display to, for instance: build channel lists; preview coming attractions; and set spending limits. Many of the same deficiencies set forth above with respect to the prior systems are evident in this system. Again, of particular relevance, is the complete lack of ability of the system itself to monitor and dynamically change user preferences inferred from the user's pattern of selection.
As discerned from the foregoing discussion, the art is devoid of teachings and suggestions for systems which provide the combined, desirable properties of: fast (virtually interactive) access time; easy updating with new information; an inexpensive communication link to the user; accessibility to virtually unlimited database size; ease of navigation; and tailored to each individual user's preferences.